Media mogul Rupert Murdoch has spoken about how he discovered his now ex-wife Wendi Deng had a “crush” on Tony Blair.

Mr Murdoch said he was in Australia when he first heard that Ms Deng had been meeting Mr Blair, a godfather to one of the former couple’s daughters, at their ranch in California without his knowledge.

He said he flew back to the US and questioned staff about what had happened.

“Well, you know, everybody was talking about these things and never telling me anything... But then I was told two pretty circumstantial things about the ranch [where Deng had been staying],” he told Fortune magazine.

“I was in Australia. When I got back, I naturally asked the staff, and it opened up. That's the story. And then, you know, a week later I filed. As soon as I could find a lawyer.”

Mr Murdoch said that after he filed for a divorce he became aware of notes written by Ms Deng, his wife of 14 years, about the former UK prime minister.

The notes, reported by Vanity Fair in February, described Mr Blair’s “good body” and his “really, really good legs” and also made a complimentary reference to his “butt”.

Mr Murdoch told Fortune that he was “shocked” by the notes, but had not read them.

“I regret the whole Vanity Fair thing. I wish we just could have got divorced quietly,” he added.

Staff reportedly told Mr Murdoch that Mr Blair had turned up at the ranch, asked where Ms Deng was and had been told she was in the bedroom.

He added: “By the time they could tell her, Blair was looking for her, they found Blair walking into the master bedroom and closing the door behind him.”

Mr Murdoch also said staff were made to feel “uncomfortable” between Mr Blair and Ms Deng were “feeding each other during dinner”.

Mr Blair has denied having an affair with Ms Deng and there is nothing to suggest that he did.